Rotary pump machine



G. E. T. EYSTON ROTARY PUMP MACHINE Filed June 23. 1930 4 Sheets-Sheet 1 llll l( 1 Nov. 15, 1932. G. E. T, EYsToN Ronny PUMP MACHINE Filed June 23, 1930 4 Sheets-Sheet 2 Nov; l5, 1932. G. E. T. EYs'roN.

ROTARY PUMP MACHINE Filed June 2s, 1930 4 sheets-sheet 5 'Nov. 15, 1932. G. E. T. EYSTON .1,887,884

ROTARY PUMP MACHINE AFiled June 25, 1930 4 Sheets-Sheet 4 Patented Nov. 1.5, 1932 UNITED As'wrrefxrrs PATENT oEEIeE,

reifer? relire .reeerrrrr Application filed .Tune 23, ii930, S'eralllo. 463,113, and in Great Britain July 18, 1929.

v' Fhis invention comprises improvements in and Connected with retery Pump and like nmeliiriee und is more particularly eoreerned with eenstructione 'of the kind eorriprslig ,a pieten :body mounted Within an enter-rotary Cylinder ,er drum and adapted, while revolv;

kindendte enable the reveluble-reeipreeatery tory metier beek forth across the space ofthe erliiiclerer drum e The eb-jeet .of the invention is te provide rlipreved eenstruetens of machine of this kind and te erieble the rerolubleri'eepreeetory piston te be eerrtrelled in Vits peeular meremeete iii e reliable end eeerlt manner.

Aeeerdrlg te this nventien, the piston is adapted delle reeipreeited bedr and forth in rlreaplrrrrpngepeee ofthe Outer Cylinder 0r drum, by forming it with t circular track which ie :irlepted fte here rolling engagement with ,e Cem er Shift mounted eccentrleelly in .the meehine- Or .-eerlvereely, @lle Bieten ,might fbe-rprerded with a eem 0r Slidell andthe ererrler breek provided in the @singel-Ure midline The eenstrueein er1- ebles .Cent-rel Of :the Dieter ,to be effected in gt reliable :monnezand Pthe rolling Contact Pil-rtsirrey beerreh aeteteke up Centrifugal f Qree er other Streeseesribstentielly Witheet freteesgivnsCerredereble advantage rthe efficient LWorking Iof the machines and eriabli-ngtbe piston V`parts to ,be made of robust construction. The c anror shaft would Vsuitably be erf-,e` diameter equal .Sevteebeuthelf the reerr@eatery= travel eftheeieton andthe track twice the diameter ofthecam or shaft. It is( Generiert telrevethe eem ,er shaft operetvetvitlihithe circular track and to'provide flete er the irterier. ofthe- -retery outer cylinder Ordrrlrr :fer the-:trerel/Qfthe pieten, and Ait Vwill Eb eseen tb-@t .rotation of the cylinder will Cerise reeuler reeiereeitierr ofthe Pisten Wltlirespee tordre leterprevdedthet there- 1e er shirt ieelrreyse eerrteetivth the nterilorwall of `the centric track and 5 (no slip oceiirs. lSlipisorily lilrelyto take place at leer speedserd tmey-belprererrted"bylnter- @ringer-@Shi 013e feller betweerrthe `Carrer sliaitlglpd :tbe interior. of the track. gQr,v as an eltererire, be arreter may here slotted portion or be formedlvvitligiiides:edaptedgto be ergegeel by er .Offset per# .0r .ertersen ,0f the eem ,ere/ heft- 111 O rderv OYFCf/'elly dead positions in the drive a, suitblegeor or leert ef e seermey .he rre-vided betr-ieee 'die com or Isllgtft epd lthe track.-r 'Ihusi'eliable starting and positive Worlgi'rig of'tli'iiicliie may be erreur-2rd lieder ellrbrrdtis- Relief of the coins or shafts from centrifugal'qrce vlinder e im a offludtakes pfllilce. This"l`1rl`iay'b`ee iile ed, referme, eymakrngrhefreeride, :or sha ft dj instable ab out x the etXfis'l o fllthe cylinder or driinif The 4piston of lenticular type arditsytpe rleveble ileiigagement lwith yraisedf flats on tbe-' lo liter cyl" der or'drum orvitfirmy beof 'otherjj`orrrrs,

for example emmerder gli Seme: eases' ie have extensions to increafsthe pumping for Workingfcpecity. Tljrerotaryiriovcm ftn'of rhePStOri .iS -Cenveriertlv' eleeted th gli the drum Whicliiriztv'hve drive ports erlg'gingtlie piston. It vismpossiblejhovveve to adopt the reverse arragenieftarid drive Clie rpm. nl outer cylinder rormvthe piston,-for instance,

if the Cain 'orshalft aforesaid Were'of su'itv able diameter it could 4be madeto rotate about its'. ovv vceiiterzzmd positivelv reciprocate 'the piston and to revolve the outer cylirider" or drum. Onboththe ,eylinderand the clam Aor Figure 4 1s a central longitudinal section,

with parts in elevation, of another construction of rotary pump machine.

`Figure 5 is a transverse section, on the lines V-V of Figure 6, of a further modified form of machine. v

Figure 6 is a sectional elevation of the same machine, the section being on the line VI-.VI of Figure 5.

Figure 7 is a view, partly in section on line VII-V'II of Figure 6, illustrating means for adjustment ofthe eccentric shaft'in Figures 5 and 6.

Figures 8 to 11 indicate diagrammatically successive phases of operation of the machine illustrated in Figures 5 and 6.

Figure 12 is a longitudinal section of one end of a machine embodying an improved form of drive. l

Figure 18 is a cross-section giving an end view of the gearing in Figure 12, and

Figure 14 is a view of the port arrangement of Figure 12.

In the machine shown in Figure 1 the piston a is'of lenticular form and operates in an outer cylinder or drum Z9 which in turn is mounted torevolve concentrically with appropriate Working clearance, in an outer casing o. The piston is adapted in its operation not only to revolve with the cylinder b butV also to reciprocate to and fro in the pumping space Z as will be described. The cylinder b as shown, has fiats e raised from the general contour of its interior surface and the piston a has fiattened tips adapted to engage and move along these fiats as the piston reciprocates. The reciprocationof the pistony may be effected by providing the machine with an eccentricallymounted stationary cam or shaft f, which is of a diameter equal to half the travel of the piston, and by forming the piston with a centric track or hole g of twice the diameter of the shaft. The cam or shaft f is preferably arrangedimmediately aboveor to one side of the axis b of the cylinder b but this is not essential though it is the simplest arrangement.

In operation, drive may b e imparted to the cylinder or drum b for example by gearing such as z, seen in Figure 4 hereinafter de- I scribed, and as the cylinder revolves, it will be 65 understood that owing tothe eccentric and stationary disposition of the cam or shaft f, the piston will be caused to reciprocate to and fro in the pumping space d along the flats e, while it is being carried round by the engagement between the flattened tip of the piston Vand the flats e. In effect, the track g of the piston rolls with the piston, round the cam or ,shaft f and the contact between the two, which cally fully exclude -air from the pumping space d at the outer end of its travel assuming that vthe sides of the piston, as shown, are given the same curvature as the interior of the cylinder. VIntake and delivery of -tir is suitably through diametrically opposite ports in the cylinder. The outer casing 'c has inlet and delivery connections Z, m, respectively on opposite sides and there will be one intake to the pumping space CZ of the cylinder a from the connection Z and delivery from such space through the connection m, past each port-lc of the cylinder during each revolution of the latter, or in other words intake and delivery will take place from the pumping space twice in each revolution of the machine.

It will be seen that the stationary cam or shaft f takes the centrifugal load on the piston and that as the contact between the cam or shaft and the interior of the piston is a rolling one, friction in the control of the piston is reduced to a minimum. Slip between the camor shaftV f and the track g which mightbe likely to take place at low speeds, may be prevented by interposing a crescentshaped bush n in the space between the cam or shaft and the track, this bush being fitted so as to rotate with the piston around the cam or shaft. It will be observed that as the centrifugalforce is taken bythe cam or shaft, the bush is not subject to this stress so that it revolves with minimum of friction. The clearance between the bush and the track g and shaft f is, of course, exaggerated in Figure 1. As an alternative to the bush a pin or roller o may be inserted between the parts as shown in Figure 2 and be adapted to roll round'the cam or shaft as the piston revolves. In each case, positive engagement between the cam or shaft and the track g can be maintained at all times with minimum friction and slip between ythe parts wholly or substantially avoided. Thus reliable starting of the machine may be ensured under all conditions. In order to overcome any dead positions in the drive the inter-engaging parts f and g might be provided with gear teeth as -seen in Figure'.` i

In the construction illustrated by Figure 4, provision is made whereby the stationary eccentric shaft of the machine, marked 7, may be relieved of centrifugal 'stresses and balance of the machine preserved. This is attained by using a plurality of the lenticular pistons and -balancin'grthem one against another. Three pistons a, a, a2 vaire shown, the two outer ones, a, a2 beingmpa'rallel'to each other "and arranged in end compartments d and the other a', equal in weight to the other two together, being disposed in a central compartment d2 `and displaced 90 from the others. The position ofthepiston a in Figure 4 corresponds with Figure l and of the pistons a, a2 with Figure 3. In the construction in Figure 4, only a single 4'eccentric vshaft f needbe fused extending through all the pistonsand-mounted on c'ranK` parts f2 at each end vin the end covers p of the machine. The crank parts f2 would 'pass centrically through the ends ofthe cylinder or drum b, which may rotate on these crank parts and the shaft might have webs-r thereon to seal with the partitions s Vbetween the different compartments of the cylinder. Driving gear is provided for 'the cylinder b or the cylinder may be driven direct. Other parts of Figure 4 corresponding to the same parts in Figure l, are similarly lettered in the two figures. If in Figure 4, bushes n or rolling parts o were used as in Figures l and 2, these mightV also be balanced one against another as described in connection with similar parts in my United States patent application Serial No. 365,648, 'filed May 24,1929.

The construction of machine illustrated in Figures 5 and 6is ofthe same general nature as that in Figure 4 buthas modified Yform of the pistons and another means-of maintaining the positive drive between the piston traclrand the eccentric shaft. It will be seen that the pistons a, af, a2 are of cylindrical form and they may also be Vprovided with. radial wings or extensions't corresponding to the tips of the pistons in Figures 1 andj4 and movable along flats e of thecylinder b. The latter may be a. plain cylindrical body with parts necessary for defining the .pump-- ing spaces d, (Z2, built up within it. F or instance the flats e may be formed on segmental parts u secured by screws o and protruding parts w be secured at each end of the flats to fit the pistons. It is not essential to'have the wings t on the pistons. If they were omitted the flats e would extend from tip to tip of the protuberances w, but it ,is.pre ferred to employ the wings as they "enable the pumping capacity of the machine'to be increased to the extent ofthe spacestraversed by these wings.

The three pistons a, Va,'a;2 are disposed Vas described withreference' to lFi'gure4, the cen-V tral pistonv ia"- of twice the l-we1ghtiand iaxial length of the others and displaced '90 with respect thereto, being seen'in full lines in Figure 5. The pumping space (Z2 of the central compartment would, lof course, also .be displaced with respect to the outer ones and similarly with the ports la of this central pumping space, exactly as in Figures. The'V pistons are adapted to Ybe guidedintheir reciprocatory movements by means of guide bars or rods which extend across the cylinder Zn parallel to .the flats e and engage with slots or surfaces of the pistons. These guides :c lmay also be the .means of causing .revolution of the pistons from the cylinder Z), thus relieving the wings t of the pistons 'of driving effort. They are secured to the partitions s and bm of thev cylinder by screws or pins as at The eccentricshaft f in this con struction is again mounted on centricv stub parts fz'andthe cylinder or drum b is mounted by its ends Z910 on antiefriction bearings y on these stub parts. The driving .gear It of thecylinder is housed in a sealed compartment e inthe left ,hand end cover p of the machine (Figure 6) and plates l are applied tothe shaft stubs ,f2 to shield the pumping spaces (Z from the bearings y.

The means vfor maintaining the rolling cony tact between the shaft f and holes or tracks g of the pistons in Figures 5 and 6 suitably .comprises disc-like parts 2 mounted and formedin olfset fashion on the shaft and adapted to engage in diametrically slotted piston parts 3 which extend at right angles to the guide bars x. `It is seen from Figure 6 that the central piston a has two rolling tracks ggg because of its greater width and that the offset 2 is centrally arranged between them, the offsets for the other pistons being at one end thereof. The axis i of the oiiset lies in a plane passing through'the axes 5 and 6 of the cylinder 5 and shaft f respe'ctively and it also 'suitably coincides with the surface of the shaft, as also does V'the axis 5, but on the opposite side. The offsets are made equal in diameter to the shaft to-simpli'fy assembly, though this is not essential, and they lit with suitable working clearance between the sides of the slots 3.

`In operation,A the bars a impart bodily rotary movement to the pistons while guiding them in their reciprocation and thusthe tips of the piston wings t may be relieved of wear and stress.4 In the reciprocation, -air is pumpedthrough the ports 7c and the inlet andpdelivery connections Z, m as before and pumping Vis effected not only bythe piston itself but also by the wings and extensions The rolling Contact between the tracks g,

and the positiveness of the rolling action is maintained'by the offsets 2 and slots 3. The guide bars 0c also assist tol this end. Owing to the arrangement ofthe bars at right angles to the slotsI 3,- it' isiclearfthat for .0^ and the shaft parts f proceeds'as before any position of the cylinder Z) and the guideY bars, there can be only one position of the slots and the rolling tracks. This will be evident if the diagrammatic views, Figures 8 and 11, showing the parts inprogressive.

round the eccentric shaft 7", Without slipping, and no bushes or gears, such as in Figures 2 and 3, arerequired to maintain the positive engagement. Y

t will be seen that in the construction of the machine shown in Figures and 6, all the revolving cylinder and piston parts are of as light construction as possible to relieve stresses. An important advantage of the invention is that the machines may possess strength combined with lightness and compactness it being possible to make the weight 30 to 35 per cent less than in the lightest of previously used types giving the same performance. In all constructions there are few working parts and these may be of a robust manufacture; simplicity is obtained in manufacture, special accuracy only being necessary with parts requiring straightforward turning` operations, for Yexample no great accuracy is necessary in-machining the parallel-sided slots 3 in which the offset shaft parts 2 work in Figures 5 and 6; advantageous balance of the forces acting is obtainable; there is only rolling Contact between the piston and its main supporting surface, the cam or shaft; and extreme simplicity in lubrication is possible.

The lubrication may advantageously be effected as shown in Figures 5 and 6, from a main duct 7 in the shaft f f2 fed by a service pipe 8 and having branch ducts, suchas 9, leadingl to the different surfaces or parts to be lubricated. A lubricant pump 10, driven by gear 11 from the gearing 7a, aforesaid, may be used for supplying the service pipe 8.

The inlet ports Z of the 4machine of Figures 5 and 6 are shown extending round the casing c for a distance about equal to the angular distance between the opposite edges such as 12, 13 of one side of the pumping spaces, and the delivery ports have about half this extent with the leading edge suitably terminating at a distance from the inlet ports equal to about the transverse width of the pumping spaces. It is advantageous in practice to be able to vary the phasing of the cylinder ports 7c with respect to the inlet and delivery ports of the outer casing c and for this purpose adjustment devices shown in Figures 6 and 7 may be used. One or both of the stubs f2 of the shaft f is fitted with means whereby the position of the shaft may be angularly adjusted about the axis of the stubs. For example, the right-hand stub in Figure 6 may be fitted with an arm 14 ex- Lacasse tending intow appropriate engagement with a;

sleeve 15 adjustable by a screw-spindle 16 so as to varyl the position of the stub angularly within the limits defined, say, by the slot 17 and key 18. In this way the position of thev eccentric shaft parts f is adjustable with respect to the rolling tracks g, g of the pistons a, a', a2 and therefore the lpoint in the revolution of the cylinderl Z2, at which the pistons will reach the ends of their-strokes is variable. Consequently, the ports le will be at different positions with respect to the inlet and delivery ports' Z, m respectively of the outer casing c of the machine, at the ends of the piston strokes and this is what is meant by varying the phasing of the cylinder ports la with respect to the ports Z, m.. The object of the adjustment vis to vary the performance of the machine to suit different requirements.

In all of theV constructions above described, the shaft f or has had a stationary or nominally stationary positionand reciprocation of the pistons has been due to the revolution; imparted to the cylinder Z9. Another arrangement, is to rotate both the cylinder and the shaft in opposite directions in the manner illustrated by Figures l2 and 13. In these figures the drive shaft ismarked 19 and carries a gear 2O which is in driving engagement both withy cylinder Z) and the stub f2 of the'ecce'ntric shaft f. Drive of the stub f2 is direct fromV gear 20 by gear 21 fixed on the stub. The cylinder, however, is driven through gearing 22, 23 and 2a. Gear 22 is meshed with gear 2O and is mounted, with gear 23, on a short lay shaft 25. Y Gear 24 is mounted or formed on the end Z210 of the cylinder'andmeshes with gear 23. The gear ratios may be of any appropriate value and it is convenient to Varrange for the stub f2 to turn at twice the speed of the cylinder, the rotation of the two part-s, of course, being in opposite directions. The advantage of this arrangement is that without increasing the speed of revolution of the cylinder Z) an increased number of pumping strokesis obtained.A For the speeds given the port arrangement shown in Figure 14 is employed, the ports beingy indicated by the same letters as are used in the constructions first described.

j A converse arrangement of the rolling contact parts in the sense already stated, comprises a xed circular track disposed eccentrically in the casing of the machine and a cam or shaft xed centrally in a piston of circular cross-section. In this case the piston, in addition to reciprocating in the cylinder would rotate-about its own axis.

I claim 1. Rotary pump or likemachine, comprising an outer casing, a hollow member mounted vto revolvev in said casing, a piston'body adapted to. reciprocate across Vsaid member .while revolving bodily therewith, said pisioo t0n body being provided with a centric track, a cam member disposed eccentrically in the machine and adapted to have rolling contact engagement with said track, and an offset partassociated with said cam memberand adaptedto engage formations ofthe piston body to prevent slip in the rolling contact engagement between said cam and track.

2. Rotary pump or like machine, comprising Yan outer casing, a revoluble member mounted-in said casing and having a transverse working space, a piston body of'cylindrical form disposed in said space and having radial extensionsoperative in extensions of the space, and means for effecting reciprocation of the piston 'body in said working space by a rolling contact control as the piston body revolves bodily with said revoluble member.

3. Rotary pump or like machine,compris ing an outer casing, a cylinder mounted to revolve concentrically therein and formed with a transverse working space, parallel guides in said space, a cylindrical piston body movable in said space in said guides, radial extensions onl said piston body movable in extensions of said space, and a shaft mounted eccentrically in the machine and adapted to have rolling contact engagement with a circular track of said piston body substantially as set forth.

4. A rotary pump or like machine comprising a revoluble working chamber, a piston adapted to reciprocate in said chamber as the latter revolves, a curved surface disposed on and non-rotatably fixed with respect to said piston and a companion curved surface disposed in the machine and engaged in continuous cycloidally rolling contact by said curved surface of said piston as the latter revolves with said working chamber.

5. A rotary pump or like machine comprising a revoluble working chamber, a piston adapted to reciprocate in said chamber as the latter revolves, a circular surface disposed on and non-rotatably fixed with respect to said piston and a companion circular surface disposed in the machine and engaged in continuous cycloidally'rolling contact byI said circular surface of said piston as the latter revolves with said working chamber.

6. A rotary pump or like machine comprisinO a revoluble working chamber, a piston adapted to reciprocate in said chamber as the latter revolves, an internally circular surface disposed on and non-rotatably fixed with respect to said piston, and an externally circular surface mounted in the machine and engaged in continuous cycloidally rolling contact by said internally circular surface of the piston as the latterY revolves with said Working chamber.

7. A rotary pump or like machine comprising a revoluble working chamber, a piston adapted to reciprocate in said chamber as the latter revolves,l a circular surface disposed on and non-rotatably fixed with respect to said piston and a companion circular surface fixed in the casing of the machine, one of ing'a revoluble working chamber, .a piston adapted to reciprocate in said chamber as the latter revolves, a circular surface disposed centrically on and non-rotatablyfixed with respect to said piston and a companion circular surface disposed eccentrically in the machine and engaged in continuous cycloidally rolling contact by said circular surface of said piston as the latter revolves with said working chamber.

l9.V A rotary pump or like machine comprising an outer casing, a cylinder, with a transverse working-space, mounted to vrevolve in said casing, a piston mounted to reciprocate in said space from sideto side of saidy cylinder, an internal surface of circularcontour formed centrically within and non-rotatably fixed `,with respect to said piston, and a. circular cam or shaft disposed eceentrically insaid casingandf engaged in vcontinuous cycloidally rolling contact by said circular surface of said pistonas the'latter.revolves with said cylinder- 10. A rotary pump or like-machine comprising a revoluble working chamber, a piston adapted to reciprocate in` said chamber as the latter revolves, a curved surface disposed .on and non-rotatablyfixed withrlrespect to said piston, a companion Vcurved surface disposedin themachine and engaged in continuous cycloidally rolling contact'by said curved surface of said piston as-the latter-revolves with said working chamber, and means operative to prevent slip between said surfaces.

' 11. A rotary pumpor like machine comprising a revoluble working chamber, a piston adapted to reciprocate in said-chamber as the latter revolves, a curved surface disposed on and non-rotatably fixed with respect to said' piston, anda companion curved surface disposed inthe machine andengaged in continuous cycloidally rolling contactby said curved surface of said piston as the lattervrevolves with said working chamber, gear teeth formations being provided on said` surfaces to prevent slip between them.

. 12. Rotary pump or like machine comprising an louter cylindrical casing provided with peripheral inlet and discharge ports, a cylinder mounted to revolve in said casing and having peripheral ports cooperative with said ports of said casing, a' piston body reciprocative between 'said ports of said cylinder, means for controlling the reciprocaton piston revolves with atAk lilo Y 4Q in this movement partaking of a cycloidal of the pistoncomprising a curved surface disposed on and non-rotatably fixed with respect to said piston and a companion curved surface disposed in said casing and engaged in continuous cycloidally rolling contact by said curved surface of said piston as the latter revolves with'said cylinder, and means for adjusting the position of said companion curved surface vfor varying thephasing of said ports of said cylinder with respect to said ports of said casing.

' 13. Rotary pump or like machine comprising an outer casing, a revoluble member mounted in said casing and having a transverse working space, a reciprocatory piston body of cylindricalV form disposed in said space with its axis extending in the same direction asthe axis of said revoluble member and means for controlling the reciprocation of said piston comprising a curved surface, disposed onA and non-rotatably fixed with relation to said piston and a companion curved surface disposed in said casing and engaged in continuous cycloidally rolling contact by said curved surface of said piston as the latter revolves with said revoluble member.

14. Rotary pump or like machine, comprising an outer casing, al cylinder mounted to revolve about the axis of said casing, a' piston body adapted to reciprocate across said cylinder while revolving bodily therewith, a circular surface disposed centrically on and non-rotatably fixed with respect to said piston, a circular cam disposed eccentrically in and mounted to be revoluble about the axis of said casing, said cylinder and cam being continuously revoluble in opposite directions on said vaxis and said circular piston surface roll in contact with and about said cam.

15. Rotary pump or like machine, comprising an outer casing, a cylinder mounted to revolve therein and formed with a transverse working space, parallel guides in said space, a cylindrical piston movable on said guides, a circular surface disposed centrically on and non-'rotatably fixed with respect to said piston, and a circular shaft disposed eccentrically in said casing 'and engaged in continuous cycloidally rolling contact bv said circular surface of said piston as the latter revolves with said cylinder.

' 16. Rotary pump or like machine, comprising an outer casing. a cylinder mounted to revolve therein and formed with a transverse working space, parallel guides in said space, a. cylindrical piston movable'on said guides, a circular surface disposed centrically on and non-rotatably fixed with respect to said piston, parallel surfaces on said piston extending at right angles to said guides, a shaft disposed eccentrically in said casing and engaged in continuous cycloidallv rolling contact by said circular surface of saidpiston as the latter revolves with said cylinder and an o'set part on said shaft engaged between said.:l: arallel surfaces of said piston.

17'. Rotary pump or like machine, comprising an outer casing provided with peripheral inlet and discharge ports, a cylinder mounted centrically in said casingV and engaged in continuous cycloidally rolling contact by said circular surface of said piston as the latter revolves with said cylinder, and an off-set part on said shaft engaged between said parallel surfaces'of said piston.

l GEORGE EDWARD THOMAS EYSTON. 

